From a5dd308778a4e05e7b0b927cf18b89d1ebbff59c Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Thu, 6 Dec 2018 11:36:04 +0100 Subject: [PATCH 1/2] net: dsa: Add overhead to tag protocol ops. Each DSA tag protocol needs to add additional headers to the Ethernet frame in order to direct it towards a specific switch egress port. It must also remove the head from a frame received from a switch. Indicate the maximum size of these headers in the tag protocol ops structure, so the core can take these overheads into account. Signed-off-by: Andrew Lunn Signed-off-by: David S. Miller --- include/net/dsa.h | 1 + net/dsa/tag_brcm.c | 2 ++ net/dsa/tag_dsa.c | 1 + net/dsa/tag_edsa.c | 1 + net/dsa/tag_gswip.c | 1 + net/dsa/tag_ksz.c | 1 + net/dsa/tag_lan9303.c | 1 + net/dsa/tag_mtk.c | 1 + net/dsa/tag_qca.c | 1 + net/dsa/tag_trailer.c | 1 + 10 files changed, 11 insertions(+) diff --git a/include/net/dsa.h b/include/net/dsa.h index 23690c44e167..6ee2e24e0a6e 100644 --- a/include/net/dsa.h +++ b/include/net/dsa.h @@ -113,6 +113,7 @@ struct dsa_device_ops { struct packet_type *pt); int (*flow_dissect)(const struct sk_buff *skb, __be16 *proto, int *offset); + unsigned int overhead; }; struct dsa_switch_tree { diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c index 2b06bb91318b..4aa1d368a5ae 100644 --- a/net/dsa/tag_brcm.c +++ b/net/dsa/tag_brcm.c @@ -174,6 +174,7 @@ static struct sk_buff *brcm_tag_rcv(struct sk_buff *skb, struct net_device *dev, const struct dsa_device_ops brcm_netdev_ops = { .xmit = brcm_tag_xmit, .rcv = brcm_tag_rcv, + .overhead = BRCM_TAG_LEN, }; #endif @@ -196,5 +197,6 @@ static struct sk_buff *brcm_tag_rcv_prepend(struct sk_buff *skb, const struct dsa_device_ops brcm_prepend_netdev_ops = { .xmit = brcm_tag_xmit_prepend, .rcv = brcm_tag_rcv_prepend, + .overhead = BRCM_TAG_LEN, }; #endif diff --git a/net/dsa/tag_dsa.c b/net/dsa/tag_dsa.c index cd13cfc542ce..8b2f92e3f3a2 100644 --- a/net/dsa/tag_dsa.c +++ b/net/dsa/tag_dsa.c @@ -149,4 +149,5 @@ static struct sk_buff *dsa_rcv(struct sk_buff *skb, struct net_device *dev, const struct dsa_device_ops dsa_netdev_ops = { .xmit = dsa_xmit, .rcv = dsa_rcv, + .overhead = DSA_HLEN, }; diff --git a/net/dsa/tag_edsa.c b/net/dsa/tag_edsa.c index 4083326b806e..f5b87ee5c94e 100644 --- a/net/dsa/tag_edsa.c +++ b/net/dsa/tag_edsa.c @@ -168,4 +168,5 @@ static struct sk_buff *edsa_rcv(struct sk_buff *skb, struct net_device *dev, const struct dsa_device_ops edsa_netdev_ops = { .xmit = edsa_xmit, .rcv = edsa_rcv, + .overhead = EDSA_HLEN, }; diff --git a/net/dsa/tag_gswip.c b/net/dsa/tag_gswip.c index 49e9b73f1be3..cb6f82ffe5eb 100644 --- a/net/dsa/tag_gswip.c +++ b/net/dsa/tag_gswip.c @@ -106,4 +106,5 @@ static struct sk_buff *gswip_tag_rcv(struct sk_buff *skb, const struct dsa_device_ops gswip_netdev_ops = { .xmit = gswip_tag_xmit, .rcv = gswip_tag_rcv, + .overhead = GSWIP_RX_HEADER_LEN, }; diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c index 0f62effad88f..96411f70ab9f 100644 --- a/net/dsa/tag_ksz.c +++ b/net/dsa/tag_ksz.c @@ -99,4 +99,5 @@ static struct sk_buff *ksz_rcv(struct sk_buff *skb, struct net_device *dev, const struct dsa_device_ops ksz_netdev_ops = { .xmit = ksz_xmit, .rcv = ksz_rcv, + .overhead = KSZ_INGRESS_TAG_LEN, }; diff --git a/net/dsa/tag_lan9303.c b/net/dsa/tag_lan9303.c index 548c00254c07..f48889e46ff7 100644 --- a/net/dsa/tag_lan9303.c +++ b/net/dsa/tag_lan9303.c @@ -140,4 +140,5 @@ static struct sk_buff *lan9303_rcv(struct sk_buff *skb, struct net_device *dev, const struct dsa_device_ops lan9303_netdev_ops = { .xmit = lan9303_xmit, .rcv = lan9303_rcv, + .overhead = LAN9303_TAG_LEN, }; diff --git a/net/dsa/tag_mtk.c b/net/dsa/tag_mtk.c index 11535bc70743..f39f4dfeda34 100644 --- a/net/dsa/tag_mtk.c +++ b/net/dsa/tag_mtk.c @@ -109,4 +109,5 @@ const struct dsa_device_ops mtk_netdev_ops = { .xmit = mtk_tag_xmit, .rcv = mtk_tag_rcv, .flow_dissect = mtk_tag_flow_dissect, + .overhead = MTK_HDR_LEN, }; diff --git a/net/dsa/tag_qca.c b/net/dsa/tag_qca.c index 613f4ee97771..ed4f6dc26365 100644 --- a/net/dsa/tag_qca.c +++ b/net/dsa/tag_qca.c @@ -101,4 +101,5 @@ static struct sk_buff *qca_tag_rcv(struct sk_buff *skb, struct net_device *dev, const struct dsa_device_ops qca_netdev_ops = { .xmit = qca_tag_xmit, .rcv = qca_tag_rcv, + .overhead = QCA_HDR_LEN, }; diff --git a/net/dsa/tag_trailer.c b/net/dsa/tag_trailer.c index 56197f0d9608..b40756ed6e57 100644 --- a/net/dsa/tag_trailer.c +++ b/net/dsa/tag_trailer.c @@ -84,4 +84,5 @@ static struct sk_buff *trailer_rcv(struct sk_buff *skb, struct net_device *dev, const struct dsa_device_ops trailer_netdev_ops = { .xmit = trailer_xmit, .rcv = trailer_rcv, + .overhead = 4, }; From dc0fe7d47f9f2256e3aa695bb754625f37291e17 Mon Sep 17 00:00:00 2001 From: Andrew Lunn Date: Thu, 6 Dec 2018 11:36:05 +0100 Subject: [PATCH 2/2] net: dsa: Set the master device's MTU to account for DSA overheads DSA tagging of frames sent over the master interface to the switch increases the size of the frame. Such frames can then be bigger than the normal MTU of the master interface, and it may drop them. Use the overhead information from the tagger to set the MTU of the master device to include this overhead. Signed-off-by: Andrew Lunn Signed-off-by: David S. Miller --- net/dsa/master.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/net/dsa/master.c b/net/dsa/master.c index c90ee3227dea..42f525bc68e2 100644 --- a/net/dsa/master.c +++ b/net/dsa/master.c @@ -158,8 +158,24 @@ static void dsa_master_ethtool_teardown(struct net_device *dev) cpu_dp->orig_ethtool_ops = NULL; } +void dsa_master_set_mtu(struct net_device *dev, struct dsa_port *cpu_dp) +{ + unsigned int mtu = ETH_DATA_LEN + cpu_dp->tag_ops->overhead; + int err; + + rtnl_lock(); + if (mtu <= dev->max_mtu) { + err = dev_set_mtu(dev, mtu); + if (err) + netdev_dbg(dev, "Unable to set MTU to include for DSA overheads\n"); + } + rtnl_unlock(); +} + int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp) { + dsa_master_set_mtu(dev, cpu_dp); + /* If we use a tagging format that doesn't have an ethertype * field, make sure that all packets from this point on get * sent to the tag format's receive function.